Butterfly valve

ABSTRACT

A butterfly valve ( 100 ) is provided according to the invention. The butterfly valve ( 100 ) includes a valve body ( 103 ) including a valve bore ( 109 ) passing through the valve body ( 103 ) and a shaft bore ( 112 ), a valve shaft ( 121 ) located in the shaft bore ( 112 ) and extending through the valve bore ( 109 ), a thermal conductor ring ( 156 ) fitted over an end of the valve shaft ( 121 ), and at least one compression ring ( 152 ) mounted to the thermal conductor ring ( 156 ) and located within the shaft bore ( 112 ). The at least one compression ring ( 152 ) fits partially into and extends partially out of a corresponding at least one ring groove ( 153 ) in the thermal conductor ring ( 156 ), with the at least one compression ring ( 152 ) substantially sealing the thermal conductor ring ( 156 ) to an actuator-side shaft bore ( 112 A).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is related to the field of valves, and more particularly,to a two-part valve.

2. Description of the Prior Art

Valves are used in a variety of applications, including in industrialenvironments, vehicles, buildings and structures, and so forth. A valveis used to regulate the flow of fluids, including liquids, gases, andmixtures thereof. The flow can include particulates in someenvironments.

Butterfly valves include a generally round flap that is rotated on ashaft, wherein the rotation can move the valve flap to extend across thevalve bore, closing the valve, or rotate the valve to extendhorizontally, aligned with the bore and opening the valve to fluid flow.The valve flap may be fully aligned with the flow in some embodiments,wherein the valve flap presents a minimal obstruction to the flow andthe valve bore is substantially unobstructed. The valve shaft and valveflap can be rotated by any suitable means, including by mechanicallinkages, by electromagnetic devices, and so forth.

Butterfly valves have many advantages. Butterfly valves are simple indesign and simple to use. Butterfly valves can offer fast responsetimes. Butterfly valves can offer minimal flow limits or obstructionswhen fully open. For these reasons, a butterfly valve is highlydesirable for regulating flow in ducts.

Butterfly valves feature a minimum of moving parts. But moreimportantly, butterfly valves have no need for small clearances ortolerances in order to function properly.

An important advantage of butterfly valves is that they are well suitedto use with hot fluids, such as hot gases. Butterfly valves are popularfor use in engine exhaust systems, as the valve flap can be made toclose reliably even in the presence of high temperatures. Further, thevalve flap-to-valve-seat contact is simple and does not require hightolerances. Dimensional changes due to heating may not render abutterfly valve inoperable or inefficient. The valve will still operateeven where the butterfly valve is subject to thermal expansion andcontraction.

However, prior art butterfly valves have drawbacks. Use with hightemperature fluids, such as hot exhaust gases, can cause damage. Hotpressurized gases can dry out lubricants and damage bearings. Hotpressurized gases can degrade seal materials, such as rubber orplastics. Thermal expansion can increase friction and binding or causeleakage due to thermal expansion or contraction.

ASPECTS OF THE INVENTION

In some aspects of the invention, a butterfly valve comprises:

-   -   a valve body including a valve bore passing through the valve        body and a shaft bore;    -   a valve shaft located in the shaft bore and extending through        the valve bore;    -   at least one compression ring located within the shaft bore,        with the at least one compression ring substantially sealing the        valve shaft to an actuator-side shaft bore.

Preferably, the at least one compression ring comprises an at leastpartially resilient ring.

Preferably, the at least one compression ring comprises a metallic ring.

Preferably, the butterfly valve further comprises a thermal conductorring fitted over an end of the valve shaft, wherein the at least onecompression ring fits partially into and extending partially out of acorresponding at least one ring groove in the thermal conductor ring,with the at least one compression ring substantially sealing the thermalconductor ring to the actuator-side shaft bore.

Preferably, the butterfly valve further comprises a thermal conductorring fitted over an end of the valve shaft, wherein the at least onecompression ring fits partially into and extending partially out of acorresponding at least one ring groove in the thermal conductor ring,with the at least one compression ring substantially sealing the thermalconductor ring to the actuator-side shaft bore and with the at least onecompression ring being removably mounted to the thermal conductor ring.

Preferably, the butterfly valve further comprises a thermal conductorring fitted over an end of the valve shaft, wherein the at least onecompression ring fits partially into and extending partially out of acorresponding at least one ring groove in the thermal conductor ring,with the at least one compression ring substantially sealing the thermalconductor ring to the actuator-side shaft bore and with the at least onecompression ring including a minimal tolerance with the at least onering groove.

Preferably, the butterfly valve further comprises a valve actuatorconfigured to couple to the valve body, with the valve actuatorincluding an actuator shaft configured to couple to the valve shaft, anda lip seal positioned over the actuator shaft of the valve actuator andabutting the valve actuator, with the lip seal being configured toprevent fluid from the valve bore from passing into the valve actuatoraround the actuator shaft.

Preferably, the butterfly valve further comprises a leakage returnconduit extending through the valve body from a valve inner matingportion to an interior valve bore surface, wherein the leakage returnconduit is configured to return any leakage fluid present at the valveinner mating portion to a downstream valve bore portion.

Preferably, the valve shaft includes a hollow portion that receives atleast a portion of an actuator shaft that extends from a valve actuator,wherein the hollow portion of the valve shaft reduces a heat transferfrom the valve shaft to the actuator shaft.

In some aspects of the invention, a butterfly valve comprises:

-   -   a valve body including a valve bore passing through the valve        body and a shaft bore;    -   a valve shaft located in the shaft bore and extending through        the valve bore, with the shaft bore including an actuator-side        shaft bore and a non-actuator-side shaft bore, with the        actuator-side shaft bore extending from an interior valve bore        surface to a valve inner mating portion of the valve body;    -   a leakage return conduit extending through the valve body from        the valve inner mating portion to the interior valve bore        surface, wherein the leakage return conduit is configured to        return any leakage fluid present at the valve inner mating        portion to a downstream valve bore portion.

Preferably, the leakage return conduit is substantially parallel to theactuator-side shaft bore.

Preferably, the leakage return conduit is non-parallel to theactuator-side shaft bore.

Preferably, the leakage return conduit is spaced a predetermined firstdistance D₁ from the actuator-side shaft bore at the valve inner matingportion.

Preferably, the leakage return conduit is spaced a predetermined seconddistance D₂ from the actuator-side shaft bore at the interior valve boresurface.

Preferably, the butterfly valve further comprises at least onecompression ring located within the shaft bore, with the at least onecompression ring substantially sealing the valve shaft to anactuator-side shaft bore.

Preferably, the butterfly valve further comprises a thermal conductorring fitted over an end of the valve shaft, wherein the at least onecompression ring fits partially into and extending partially out of acorresponding at least one ring groove in the thermal conductor ring,with the at least one compression ring substantially sealing the thermalconductor ring to the actuator-side shaft bore.

Preferably, the butterfly valve further comprises a valve actuatorconfigured to couple to the valve body, with the valve actuatorincluding an actuator shaft configured to couple to the valve shaft, anda lip seal positioned over the actuator shaft of the valve actuator andabutting the valve actuator, with the lip seal being configured toprevent fluid from the valve bore from passing into the valve actuatoraround the actuator shaft.

Preferably, the valve shaft includes a hollow portion that receives atleast a portion of an actuator shaft that extends from a valve actuator,wherein the hollow portion of the valve shaft reduces a heat transferfrom the valve shaft to the actuator shaft.

In some aspects of the invention, a butterfly valve comprises:

-   -   a valve body including a valve bore passing through the valve        body and a shaft bore;    -   a valve shaft located in the shaft bore and extending through        the valve bore;    -   a valve actuator configured to couple to the valve body, with        the valve actuator including an actuator shaft configured to        couple to the valve shaft; and    -   a lip seal positioned over the actuator shaft of the valve        actuator and abutting the valve actuator, with the lip seal        being configured to prevent fluid from the valve bore from        passing into the valve actuator around the actuator shaft.

Preferably, the lip seal is formed of an at least partially flexiblematerial.

Preferably, the lip seal is formed of an at least partially resilientmaterial.

Preferably, the lip seal is formed of an at least partially compressiblematerial.

Preferably, the lip seal comprises a first annular seal portionextending radially inward, a second annular seal portion extendingradially inward and substantially parallel to the first annular sealportion, and a web portion extending between and joining the secondannular seal portion to the first annular seal portion.

Preferably, the valve shaft includes a hollow portion that receives atleast a portion of the actuator shaft.

Preferably, the valve shaft includes a hollow splined portion thatreceives at least a portion of the actuator shaft.

Preferably, the valve shaft includes a hollow splined portion thatreceives at least a portion of the actuator shaft, wherein the hollowsplined portion allows thermal expansion and contraction of the valveshaft without affecting the coupling between the actuator shaft and thevalve shaft.

Preferably, the valve shaft includes a hollow portion that receives atleast a portion of the actuator shaft, wherein the hollow portionreduces a heat transfer from the valve shaft to the actuator shaft.

Preferably, the butterfly valve further comprises at least onecompression ring located within the shaft bore, with the at least onecompression ring substantially sealing the valve shaft to anactuator-side shaft bore.

Preferably, the butterfly valve further comprises a thermal conductorring fitted over an end of the valve shaft, wherein the at least onecompression ring fits partially into and extending partially out of acorresponding at least one ring groove in the thermal conductor ring,with the at least one compression ring substantially sealing the thermalconductor ring to the actuator-side shaft bore.

Preferably, the butterfly valve further comprises a leakage returnconduit extending through the valve body from a valve inner matingportion to an interior valve bore surface, wherein the leakage returnconduit is configured to return any leakage fluid present at the valveinner mating portion to a downstream valve bore portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The same reference number represents the same element on all drawings.It should be understood that the drawings are not necessarily to scale.

FIG. 1 shows a two-part butterfly valve according to the invention.

FIG. 2 shows detail of the butterfly valve according to the invention.

FIG. 3 is an exploded view of the butterfly valve according to theinvention.

FIGS. 4-5 are section views that show detail of the junction between avalve assembly and actuator according to the invention.

FIG. 6 is a cross-section of an actuator end of a valve shaft, showingdetail of a thermal conductor ring and a compression ring.

FIG. 7 shows the compression ring according to the invention.

FIG. 8 shows the compression ring according to the invention.

FIG. 9 shows detail of a leakage return conduit according to theinvention.

FIG. 10 shows detail of a lip seal according to the invention.

FIG. 11 is a section view through the valve assembly of the butterflyvalve.

FIG. 12 is a section view of the valve flap in a closed position.

FIG. 13 shows a high-temperature butterfly valve according to theinvention.

FIG. 14 shows the mating regions of the valve assembly and the valveactuator.

FIG. 15 shows the mating regions of the valve assembly and the valveactuator.

FIG. 16 shows detail of the mating regions of the valve assembly and thevalve actuator.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1-16 and the following description depict specific examples toteach those skilled in the art how to make and use the best mode of theinvention. For the purpose of teaching inventive principles, someconventional aspects have been simplified or omitted. Those skilled inthe art will appreciate variations from these examples that fall withinthe scope of the invention. Those skilled in the art will appreciatethat the features described below can be combined in various ways toform multiple variations of the invention. As a result, the invention isnot limited to the specific examples described below, but only by theclaims and their equivalents.

FIG. 1 shows a butterfly valve 100 according to the invention. Thebutterfly valve 100 includes a valve assembly 110 and an actuator 123coupled to the valve assembly 110. The valve assembly 110 includes avalve body 103, a valve bore 109 extending through the valve body 103,and a valve flap 107 configured to rotate within the valve bore 109 on avalve shaft 121. The valve body 103 can include flanges 104 and 104′and/or other attachment features that enable the butterfly valve 100 tobe assembled to other components or devices. The butterfly valve may beused for regulating fluids of varying temperatures, such as where thefluid may cause thermal expansion and thermal contraction of thebutterfly valve.

The actuator 123 comprises a device that is capable of rotating thevalve shaft 121 and therefore rotating the valve flap 107. The actuator123 includes an actuator shaft 126 or other rotational member thatcouples to the valve shaft 121. The actuator shaft 126 can comprise asplined shaft, keyed shaft, shaped shaft, or any shaft configurationthat transfers rotational movement (see FIG. 4). The actuator 123 cancomprise any manner of rotational actuator, including mechanical,electrical/magnetic, pneumatic, hydraulic, or other actuator devices.The actuator 123 can be affixed to the valve assembly 110 in any manner.For example, the actuator 123 can be removably affixed to the valveassembly 110 by a clamp 130 (see FIG. 2 and the accompanying discussionbelow).

In some embodiments, the actuator 123 can include a fluid cooling system225 (see FIG. 13 and the accompanying discussion). The fluid coolingsystem 225 can include a cooling liquid or cooling gas that is used todraw heat away from the actuator 123. The fluid cooling system 225 cantransfer heat out of the actuator 123. The fluid cooling system 225 canbe static or can including circulation of a cooling liquid or coolinggas.

Where the valve assembly 110 is used for regulating hot liquids or hotgases, most heat transfer will occur at the junction between the twocomponents. Such heat transfer is generally not desired. Consequently,the butterfly valve 100 includes features that minimize heat transferand/or conducts transferred heat through certain components. As aresult, heat transfer to the actuator 123 is minimized and controlled,wherein the operational life of the actuator 123 is improved.

Significant heat transfer into the actuator 123 may cause problems. Theheat transfer may dry out or damage bearings. The heat transfer mayincrease electrical resistance and increase power consumption. The heattransfer may affect actuation speed and/or actuation response times. Theheat transfer may cause components to change size and/or changetolerances due to thermal expansion and thermal contraction.

FIG. 2 shows detail of the butterfly valve 100 according to theinvention. This figure shows a valve flange 105 and a correspondingshaft bore 112, an actuator flange 124, and a spacer (or washer) 150that is received and trapped between the two main components.

The spacer 150 can seal between the two components. To that end, thespacer 150 can be at least partially resilient and/or partiallycompressible. The spacer 150 can be of a thickness wherein the valveflange 105 and the actuator flange 124 must at least partially compressthe spacer 150 before the two flanges come into contact. Alternatively,the joint can be vented or may not need to be fluid tight. It should beunderstood that alternatively the spacer 150 can be replaced by athermal insulator gasket 157 and/or a thermal conductor ring 156 (seeFIG. 3, for example, and the accompanying discussion).

The spacer 150 can comprise a friction element that at least partiallyprevents rotation of the two valve components when clamped between thetwo flanges. The friction characteristic can be provided by theresilient/compressible nature of the spacer 150, for example.

The figure shows detail of an embodiment of the clamp 130. In thisembodiment, the clamp 130 comprises first and second clamp portions 133and 134. In another embodiment, the clamp 130 can comprise a singlepiece with one split, wherein only a single tightening device 136 isneeded. A joiner mechanism 132 joins the two clamp portions at one pointand a tightening device 136 joins the other ends. The joiner mechanism132 can comprise a mechanical arrangement, including a disengageablemechanism, such as the buckle and loops shown. However, other mechanismscan be employed. For example, the clamp 130 can be constructed with twotightening devices 136.

The tightening device 136 can be manipulated to constrict the clamp 130,as previously discussed. Therefore the tightening device 136 can bringtogether ends of the first and second clamp portions 133 and 134. In theembodiment shown, the tightening device 136 comprises a threadedfastener. The threaded fastener can comprise a nut and bolt, but cancomprise other configurations, such as a threaded screw that engages anaperture (or threaded aperture) in a clamp portion end.

The internal shape of the clamp 130 acts to force together the twoflanges. The internal shape can therefore be substantially rectangular,with perpendicular sidewalls. Alternatively, the sidewalls can beangled, curved, or other desired shapes.

The figure further shows an alignment feature 162 extending from thevalve flange 105. The alignment feature 162 can be of any shape or size.The alignment feature 162 in some embodiments comprises a dowel. Thealignment feature 162 engages a substantially corresponding aperture,notch, depression, et cetera (not shown) in the actuation flange 124.The alignment feature 162 can therefore align the valve actuator 123with the valve body 103 during assembly. Advantageously, the alignmentfeature 162 in some embodiments may assist in aligning the actuatorshaft 126 with the valve flap 107 of the valve mechanism 103. Further,the alignment feature 162 can prevent rotation of the valve actuator 123with respect to the valve body 103.

FIG. 3 is an exploded view of the butterfly valve 100 according to theinvention. As discussed above, the actuator 123 includes an actuatorshaft 126 and an alignment feature 162. The valve assembly 110 includesthe valve body 103, the valve bore 109 passing through the valve body103, and the shaft bore 112 extending across the valve body 103 andsubstantially transverse to the valve bore 109. The shaft bore 112 isinterrupted by the valve bore 109 and comprises shaft bore portions 112Aand 112B. The valve shaft 121 is located within the shaft bores 112A and112B and may rotate within the valve body 103.

The valve shaft 121 includes one or more flap fastener bores 118 thatreceive one or more corresponding flap fasteners 108. The valve flap 107is affixed to the valve shaft 121 by one or more flap fasteners 108. Theone or more flap fasteners 108 can comprise any suitable fasteners. Theone or more flap fasteners 108 can permanently or removably affix thevalve flap 107 to the valve shaft 121.

The non-actuator end of the valve shaft 121 receives a shaft bearing orbushing 142 and an end seal 145. The shaft bearing 142 fits over thevalve shaft 121 and allows the valve shaft 121 to rotate in the shaftbore portion 112B. The end seal 145 can comprise a plug that is pressfit or otherwise removably or permanently affixed in the end of theshaft bore 112B, thereby substantially sealing the end of the shaft bore112B. Neither the valve shaft 121, nor gas or liquid in the valveassembly 110, can escape from the shaft bore portion 112B as a result ofinstallation of the end seal 145.

The actuator end of the valve shaft 121 receives a shaft bearing 140, atleast one compression ring 152, a thermal conductor ring 156, a thermalinsulator gasket 157, and a lip seal 159. The shaft bearing 140 fitsover the valve shaft 121 and is received in the shaft bore 112A, similarto the shaft bearing 142. The valve shaft 121 can rotate in the shaftbearing 140. The shaft bearing 140, when assembled to the valve shaft121 and the valve body 103, will substantially abut the thermalconductor ring 156. The shaft bearings 140 and 142 may absorb any axialloads exerted by the valve flap 107 and the valve shaft 121.

The actuator shaft 126 may be splined (see FIG. 14), keyed, or otherwiseshaped so that a hollow end of the valve shaft 121 fits over theactuator shaft 126 and rotational movement is transferred therebetween.The actuator shaft 126 may be held in place in relation to the valveshaft 121 by the clamp 130. Alternatively, the actuator shaft 126 mayinclude a snap ring or other retainer device.

The snap ring 151 fits into a groove or channel on the protrudingactuator shaft 126. The snap ring 151 also fits into a snap ring groove128 formed inside a hollow portion 129A of the valve shaft 121 (see FIG.6 and the accompanying text). Consequently, the actuator shaft 126 andthe valve shaft 121 are held together in some embodiments. As a result,axial loads on the valve shaft 121 are transmitted into the actuator123. Such axial loads may arise from fluid pressure and/or fluid flow,including from forces acting on the valve flap 107. Because the bushings140 and 142 do not have to absorb or control axial shaft loads, thebushings 140 and 142 will offer less rotational resistance in someembodiments.

The thermal insulator gasket 157 is located between the valve assembly110 and the actuator 123. The thermal insulator gasket 157 seals betweenthe valve assembly 110 and the actuator 123. The thermal insulatorgasket 157 is held in place when the clamp 130 is applied to the valvebody flange 105 and the actuator flange 124. In addition, the thermalinsulator gasket 157 may be formed of a material that has a low heattransfer property. As a result, the thermal insulator gasket 157 reducesor prevents heat transfer between the valve body 103 and the actuatorhousing 127. Further, the thermal insulator gasket 157 prevents fluidfrom escaping at the junction of the actuator 123 and the valve assembly110.

The compression ring 152 fits onto the thermal conductor ring 156 (seeFIG. 6, for example). The compression ring 152 may fit into acorresponding ring groove 153 formed in the thermal conductor ring 156.The compression ring 152 may be removably mounted to the thermalconductor ring 156. The compression ring 152 may be formed or machinedto have a relatively tight tolerance with the ring groove 153. Further,the compression ring 152 may be at least partially flexible andcompressible, wherein the compression ring 152 must be compressedsomewhat in order for the compression ring 152 and the thermal conductorring 156 to be inserted into the actuator-side shaft bore 112A. As aresult, the compression ring 152 substantially seals the thermalconductor ring 156 to the inner surface of the actuator-side shaft bore112A. Consequently, the thermal conductor ring 156 can conduct heatbetween the valve assembly 110 and the actuator 123, but fluid withinthe valve assembly 110 cannot leak to the actuator 123 or escape at thejunction of the valve assembly 110 and the actuator 123.

The compression ring 152 comprises a metallic ring in some embodiments.Alternatively, the compression ring 152 can be formed from hightemperature plastic or any material that is not degraded by hightemperatures and that can be compressed at least somewhat.

The thermal conductor ring 156 is located between the valve assembly 110and the actuator 123. The thermal conductor ring 156 in some embodimentsis configured and sized to fit tightly over the end of the valve shaft121 so that no fluid can travel between the valve shaft 121 and thethermal conductor ring 156. The thermal conductor ring 156 may be formedof a material having a relatively high thermal transfer characteristic,so that heat present in the end of the valve shaft 121 may be conductedto the actuator housing 127. This may draw some heat away from theactuator shaft 126.

FIGS. 4-5 are section views that show detail of the junction between thevalve assembly 110 and the actuator 123 according to the invention. Theend of the valve shaft 121 includes a hollow portion 129A. The hollowportion 129A corresponds to and fits over the actuator shaft 126. Thehollow portion 129A in some embodiments comprises a hollow splinedportion 129A. The hollow splined portion 129A fits over acorrespondingly splined portion of the actuator shaft 126, wherein thesplines transmit the rotation of the actuator shaft 123 to the valveshaft 121. The hollow portion 129A additionally presents a much lowerheat transfer capacity, wherein less heat is able to be conducted by thevalve shaft 121 to the actuator 123 due to the hollow portion 129A.

The lip seal 159 is configured to fit over the actuator shaft 126 andsubstantially seal the actuator shaft 126 to an inner surface of theactuator housing 127. One lip of the lip seal 159 (i.e., the inner lip)will sealingly contact the actuator shaft 126, while the other lip(i.e., the outer lip) will sealingly contact the inner surface of theactuator housing 127 (see FIG. 10 and the accompanying discussionbelow). The lip seal 159 is configured to seal around the actuator shaft126 and to prevent fluids from the valve bore 109 from reaching theinterior of the actuator 123. The lip seal 159 is held in place withinthe actuator housing 127.

The lip seal 159 is preferably formed of a resilient material, such asrubber or a rubber compound, and may be degraded by excessive heat. Forthis reason, it is desirable to minimize the amount of heat absorbed bythe actuator housing 127, such as by the portion of the actuator housing127 that is adjacent to the valve assembly 110.

FIG. 6 is a cross-section of the actuator end of the valve shaft 121,showing detail of the thermal conductor ring 156 and the compressionring 152. It should be understood that the shaft bearing 140 is includedto hold the valve shaft 121 in place and allow the valve shaft 121 tofreely rotate. Further, or alternatively, the valve shaft 121 caninclude a snap ring groove 128 that receives the snap ring 151. The snapring 1561 may rest in the snap ring groove 128 and may engage acorresponding groove or other feature in the actuator shaft 126.

However, the shaft bearing 140 may not seal between the valve shaft 121and the shaft bore 112A. The valve shaft is often a leakage path. Whenthe valve is closed or nearly closed, there is high pressure on theupstream side of the valve 109U and low pressure on the downstream side109D. The resulting large pressure differential causes the upstreampressurized fluid to travel into the area around the valve shaft 121 inorder to skirt the valve flap 107. This is especially true where thevalve flap 107 is not on one side or the other of the valve shaft 121,so that the valve shaft 121 is in fluid communication with both theupstream and downstream sides of the valve bore 109.

At least one compression ring 152 is mounted to the thermal conductorring 156 and is located within the actuator-side shaft bore 112A. Thecompression ring 152 fits partially into and extends partially out of acorresponding ring groove 153 in the thermal conductor ring 156 in someembodiments. The compression ring 152 substantially seals the thermalconductor ring 156 to the actuator-side shaft bore 112A.

The compression ring 152 is designed to be under at least somecompression and therefore substantially contacts and presses outwardlyagainst the inner surface of the shaft bore 112A. In addition, thetolerances may be designed so that the compression ring 152substantially contacts the sides of the ring groove 153, whereinpressurized fluid cannot pass underneath the compression ring 152. As isshown in the figure, there may be a clearance space below thecompression ring 152. Consequently, little or no pressurized fluid willbe able to pass around the valve shaft 121 and the thermal conductorring 156.

FIG. 7 shows the compression ring 152 according to the invention. Thecompression ring 152 can comprise a substantially annular shape and apredetermined thickness T. The compression ring 152 includes an aperture138 in the substantially planar, annular body. However, it should beunderstood that the compression ring 152 can have variouscross-sectional shapes and is not limited to the substantiallyrectangular cross-sectional shape shown in the figure.

The compression ring 152 in this embodiment includes a gap 139. The gap139 may be sized to allow a predetermined amount of compression.

The compression ring 152 may be formed of any suitable material. Thecompression ring 152 is at least partially resilient and therefore atleast partially compressible. In some embodiments, the compression ring152 may be at least partially metallic in composition. In someembodiments, the compression ring 152 may be at least partially plasticin composition. However, it should be understood that any suitablematerial may be used for the compression ring 152.

FIG. 8 shows the compression ring 152 according to the invention. Inthis embodiment, the compression ring 152 comprises a substantiallyplanar, annular body with the aperture 138 therethrough. In thisembodiment, however, the body is divided into two portions, a firstsplit portion 152A and a second split portion 152B, with the two splitportions having the predetermined thicknesses T₁ and T₂. The thicknessesT₁ and T₂ may be the same or different. A split 148 exists between thetwo split portions 152A and 152B, with each split portion ending in gaps139A and 139B. This design allows the compression ring 152 to becompressed, but with even better sealing properties.

The first gap 139A and the second gap 139B may be of any desired size,as discussed above, wherein the first and second gaps 139A and 139Ballow the compression ring 152 to be compressed. The first gap 139A isoffset from the second gap 139B by a predetermined circumferential (orangular) distance. As a result, there is no clear, unobstructed gap forfluid to escape through. Further, if fluid pressure exists on the frontsurface of the compression ring 152, then the front split portion 152Amay be pressed against the rear split portion 152B, wherein the split148 becomes compressed and negligible in size.

FIG. 9 shows detail of a leakage return conduit 163 according to theinvention. The butterfly valve may be used for regulating fluids ofvarying pressures, including where fluid pressure may cause leakagearound a valve shaft bore 112. The leakage return conduit 163 does notallow fluid to escape externally. The leakage return conduit 163 extendsthrough the valve body 103 from a valve inner mating portion 172 to theinterior valve bore surface 171. The leakage return conduit 163 isconfigured to return any leakage fluid present at the valve inner matingportion 172 to a downstream valve bore portion 109D. However, it shouldbe understood that the leakage return conduit 163 does not allow leakagefluids to escape the butterfly valve 100, as commonly occurs in theprior art. As a consequence, the leakage return conduit 163 is thereforenot an access port for moisture, dirt, or other foreign matter to getinside the butterfly valve 100. The leakage return conduit 163 is spaceda predetermined first distance D₁ from the actuator-side shaft bore 112Aat the valve inner mating portion 172. The leakage return conduit 163 isspaced a predetermined second distance D₂ from the actuator-side shaftbore 112A at the interior valve bore surface 171. The leakage returnconduit 163 may be substantially parallel to the actuator-side shaftbore 112A. Alternatively, the leakage return conduit 163 may benon-parallel to the actuator-side shaft bore 112A.

The leakage return conduit 163 may be of a predetermined cross-sectionalarea. The cross-sectional area may be chosen according to an expectedleakage volume or leakage rate. The cross-sectional area may be chosento accommodate an average expected leakage, a minimum expected leakage,a maximum expected leakage, or other desired value.

Some leakage may occur past the shaft bearing 140. Most leakage will notescape past the thermal conductor ring 156 in combination with thecompression ring 152. However, a smaller level of leakage may occur pastthe thermal conductor ring 156 in combination with the compression ring152. This leakage will travel between the valve inner mating portion 172of the valve body 103 and the thermal insulator gasket 157 andconsequently enter the leakage return conduit 163. This is aided by thepressure differential between the upstream side 109U of the valve bore109 with respect to the downstream side 109D. This positive pressuredifferential may create a venturi effect in the leakage return conduit163, drawing any fluid leakage into the leakage return conduit 163 andtherefore to the downstream side 109D of the valve bore 109.

FIG. 10 shows detail of the lip seal 159 according to the invention. Thelip seal 159 is positioned over the actuator shaft 126 of the valveactuator 123 and abuts the valve actuator 123. The lip seal 159 may abutand contact the actuator housing 127 (see FIG. 5). The lip seal 159 isconfigured to prevent any fluid in the actuator-side shaft bore 112Afrom passing into the valve actuator 123 around the actuator shaft 126.

The lip seal 159 comprises a first annular seal portion 164 extendingradially inward, a second annular seal portion 166 extending radiallyinward and substantially parallel to the first annular seal portion 164,and a web portion 165 extending between and joining the second annularseal portion 166 to the first annular seal portion 164. The firstannular seal portion 164 may include an enlarged portion 167, as shown.The enlarged portion 167 can be substantially rectangular in shape, asshown. Alternatively, the enlarged portion 167 can be diamond shaped,circular or elliptical, regular or irregular, or any other suitableshape. It should be understood that the second annular seal portion 166may also include an enlarged portion, if desired.

The first annular seal portion 164 is configured to sealingly contactthe actuator shaft 126, even when the actuator shaft 126 is rotating.The second annular seal portion 166 is configured to sealingly contactthe actuator housing 127.

The lip seal 159 may be formed of an at least partially flexiblematerial. The lip seal 159 may be formed of an at least partiallyresilient material. The lip seal 159 may be formed of an at leastpartially compressible material.

FIG. 11 is a section view through the valve assembly 110 of thebutterfly valve 100. This view shows the valve flap 107 mounted to thevalve shaft 121 by the one or more flap fasteners 108. The figure alsoillustrates the valve bore 109. The valve bore 109 includes boreshoulders 183 that are configured to be substantially sealinglycontacted by the valve flap 107 when the valve flap 107 is in a closedposition.

In the embodiment shown, the valve bore 109 comprises an upstream valvebore portion 109U and a downstream valve bore portion 109D, wherein theupstream valve bore portion 109U and the downstream valve bore portion109D are substantially separated by the valve flap 107 when the valveflap 107 is in a closed position. It should be understood that the termsupstream and downstream are used in context of the fluid entering fromthe left side in the figure. Fluid could flow in the opposite directionthrough the valve bore 109, but some of the advantages would then not berealized in the butterfly valve 100.

The bore shoulders 183 in some embodiments can comprise an upper boreshoulder 183A and a lower bore shoulder 183B. The upper bore shoulder183A and the lower bore shoulder 183B may not necessarily form a singlecontinuous surface. In the embodiment shown, the valve shaft 121interrupts the upper bore shoulder 183A and the lower bore shoulder183B. The upper bore shoulder 183A can face the upstream valve boreportion 109U, while the lower bore shoulder 183B can face the downstreamvalve bore portion 109D.

The valve flap 107 includes a face seal 179. The face seal 179 in theembodiment shown can comprise a substantially planar annular surfacethat is configured to substantially seal against the bore shoulders 183.Likewise, the bore shoulders 183 can be substantially planar and annularin shape, although the bore shoulders 183 can comprise two separateshoulder sections. The face seal 179 can be configured to substantiallylap over the bore shoulders 183 and sealingly contact the bore shoulders183, but yet while allowing the valve flap 107 to thermally expand andcontract. As a result, at least a portion of the flap seal 179 will fitto and substantially lap over at least a portion of the bore shoulders183 when the valve flap 107 is rotated to the fully closed position. Theflap seal 179 can be formed with sufficient radial clearance to avoidthe sides of the valve bore 109.

By not sealing against the wall of the valve bore 109, as is done in theprior art, the face seal feature of the present invention avoids thermalexpansion problems. Expansion and contraction of the material of thevalve flap 107 does not result in binding against the valve bore 109.Expansion and contraction of the material of the valve flap 107therefore does not place additional loads on the valve shaft seals,bushings, or bearings. Further, in the prior art, as the bushings orbearings wear over the life of the valve, the peripheral prior art sealis negatively affected. Advantageously, the face seal 179 hereindescribed is not negatively affected by worn or loose bushings orbearings.

Even where the valve flap 107 exhibits thermal expansion, the designavoids clearance problems while yet maintaining a significant andsatisfactory seal contact area. The flap seal 179 and the bore shoulders183 allow sealing contact without the need for close tolerances.Further, fluid pressure on the upstream valve bore portion 109U willserve to increase the closing pressure of the valve flap 107 on theupper bore shoulder 183A, offsetting the opening pressure exerted by thefluid with regard to the lower bore shoulder 183B.

Both the upstream valve bore portion 109U and the downstream valve boreportion 109D are tapered in some embodiments. The tapered upstream valvebore portion 109U and the tapered downstream valve bore portion 109D mayprovide ramped steps in the valve bore 109, as shown. The ramped stepsmay provide a substantially constant flow area through the length of thevalve body 103. The ramped steps may reduce drag as the fluid flowsthrough the valve bore 109, with the ramped steps smoothly conduct fluidtoward and away from the bore shoulders 183.

The valve flap 107 is offset on the valve shaft 121 in some embodiments.This is unlike the prior art, where the prior art butterfly valve flapis typically centered on the valve shaft. The offset is on the side ofthe upstream valve bore portion 109U. A benefit of this mountingarrangement is that the incoming fluid is physically isolated from thevalve shaft 121. Consequently, the fluid pressure will press the valveflap 107 against the valve shaft 121. The one or more flap fasteners 108will only hold the valve flap 107 in position, and will not need toretain the valve flap 107 against a fluid pressure.

Another benefit of this mounting arrangement is that the incoming fluidis thermally isolated from the valve shaft 121. This greatly reducesheat transfer from the fluid to the valve shaft 121. As a result, thebearings, seals, and actuator mechanism of the butterfly valve 100 willhave a longer operational life. Less heat transfer will cause lessdamage to soft and easily temperature-damaged seal materials, such asrubber, for example. Less heat transfer will cause less drying out oflubricants. Less heat transfer will cause less thermal expansion andcontraction and therefore less thermal warping, less wear, and lessbinding. Less heat transfer will cause less electrical resistance.

FIG. 12 is a section view of the valve flap 107 in a closed position.The valve flap 107 is affixed to the upstream valve bore portion side ofthe valve shaft 121, on the side of the upstream valve bore portion 109Uof the valve bore 109 with respect to the valve shaft 121. The incomingfluid (see arrows) presses the valve flap 107 against the valve shaft121.

In the closed position, the flap seal 179 of the valve flap 107substantially sealingly contacts the one or more bore shoulders 183 ofthe valve bore 109. In some embodiments, the flap seal 179 comprises asubstantially planar annular surface. Similarly, the one or more boreshoulders 183 in some embodiments comprises a substantially planarannular surface, wherein the flap seal 179 is configured to fitsubstantially flatly against the one or more bore shoulders 183.

In the embodiment shown, the valve flap 107 is substantially transverseto the valve bore 109 when the valve flap 107 is in the closed position.However, the closed position of the valve flap 107 may be determined bythe positions of the bore shoulders 183, and does not have to bestrictly transverse to the fluid flow.

It can be seen from the figure that a gap may exist between the outercircumferential edge of the flap seal 179 and the valve bore 109. Thisgap allows thermal expansion and thermal contraction of the valve flap107 (and of the valve bore 109). This gap does not have to be of a smalltolerance. Any changes in the size of the gap due to thermal expansionor contraction will not affect the seal between the flap seal 179 andthe one or more bore shoulders 183.

The valve flap 107 is preferably formed of a material having a low heattransfer characteristic. As a consequence, the valve flap 107 willtransfer relatively little heat from the fluid to the valve shaft 121,including when the valve flap 107 is in the closed position. In someembodiments, one or both of the flap seal 179 and the one or more boreshoulders 183 are formed of metal. The valve flap 107 alternatively mayinclude a sealing material on the flap seal 179, but the sealingmaterial will need to be able to withstand high temperatures withoutdegrading.

It can be seen from this figure that the valve flap 107 physicallyshields the valve shaft 121 from the upstream pressure of the fluid. Thevalve flap 107 physically shields the valve shaft 121 from thebackpressure created when the valve is closed or nearly closed. Inaddition, the valve flap 107 thermally shields the valve shaft from theincoming fluid in the upstream valve bore portion 109U, and especiallywhen the valve flap 107 is in the closed position.

FIG. 13 shows a high-temperature butterfly valve 100 according to theinvention. The high-temperature butterfly valve 100 includes the valveassembly 110 according to any of the embodiments herein. Thehigh-temperature butterfly valve 100 includes a valve actuator 123 thatincludes a fluid cooling system 225 according to some embodiments of theinvention. The fluid cooling system 225 includes one or more coolingducts 227 that extend to, and are in thermal communication with, theactuator flange 124. The actuator flange 124 is designed to mate to thevalve flange 105 of the valve assembly 110. The fluid cooling system 225can provide cooling fluid to at least part of the actuator flange 124and can receive cooling fluid back. The fluid cooling system 225 cancirculate cooling fluid to the actuator flange 124 in order to removeheat from the actuator flange 124, and nearby portions of the valveactuator 123. Further, the fluid cooling system 225 can include ducts inother parts of the valve actuator 123, wherein various portions of thevalve actuator 123 can be thermally regulated.

The fluid cooling system 225 can be contained within the valve actuator123. Alternatively, portions or components of the fluid cooling system225 can extend outside valve actuator 123. For example, the fluidcooling system 225 can include a heat exchanger device or devices thatare located outside the valve actuator 123, wherein the cooling fluid iscirculated through the valve actuator 123.

The cooling fluid can comprise a liquid in some embodiments. The coolingfluid can comprise a gas in some embodiments. Alternatively, the coolingfluid can comprise portions of liquid and gas, as desired.

FIG. 14 shows the mating regions of the valve assembly 110 and the valveactuator 123, comprising the valve flange 105 (the left image in thefigure) and the actuator flange 124 (the right image). The valve flange105 includes a valve outer mating portion 174 and a valve inner matingportion 172. The actuator-side shaft bore 112A may be at substantiallythe center of the valve flange 105, with the actuator-side shaft bore112A receiving the valve shaft 121. This figure shows the splines 122 inthe hollow portion 129A of the valve shaft 121 and substantiallycorresponding splines 125 on the actuator shaft 126.

The valve outer mating portion 174 and the valve inner mating portion172 can comprise substantially annular, planar faces in someembodiments. The valve inner mating portion 172 may be recessed withrespect to the valve outer mating portion 174, as shown, or may besubstantially co-planar or may extend outward past the valve outermating region 174. The valve outer mating portion 174 and the valveinner mating portion 172 may be substantially concentric in someembodiments. The relative sizes of the valve outer mating portion 174and the valve inner mating portion 172 are not necessarily to scale anddo not necessarily represent desired or actual proportions.

Similarly, the valve actuator 123 includes an actuator inner matingportion 182 and an actuator outer mating portion 184. The actuator shaft126 may be substantially at the center of the actuator flange 124 andconfigured to engage the valve shaft 121 of the valve assembly 110. Theactuator inner mating portion 182 and the actuator outer mating portion184 can comprise substantially annular, planar faces in someembodiments. The actuator inner mating portion 182 may be recessed withrespect to the actuator outer mating portion 184, as shown, or may besubstantially co-planar or may extend outward past the actuator outermating region 184. The actuator inner mating portion 182 and theactuator outer mating portion 184 may be substantially concentric insome embodiments. The relative sizes of the actuator inner matingportion 182 and the actuator outer mating portion 184 are notnecessarily to scale and do not necessarily represent desired or actualproportions.

In the high-temperature butterfly valve 100 embodiments, at least asubregion of the actuator inner mating portion 182 can be in thermalcontact with the fluid cooling system 225. Alternatively, according tothe design and cooling needs of the valve actuator 123, the entireactuator inner mating portion 182 can be in thermal contact with thefluid cooling system 225. Consequently, the fluid cooling system 225 canremove heat from the actuator inner mating portion 182, such as heatthat is received from the valve assembly 110.

FIG. 15 shows the mating regions of the valve assembly 110 and the valveactuator 123. When the valve actuator 123 is assembled to the valveassembly 110, the valve outer mating portion 174 of the valve assembly110 may at least partially contact the actuator outer mating portion 184of the valve actuator 123. The valve outer mating portion 174 may notnecessarily match the actuator outer mating portion 184 in size orshape. The resulting minimal contact area between the valve flange 105and the actuator flange 124 advantageously minimizes heat transferbetween the two components, as both the valve body 103 and the actuatorhousing 127 may be formed of metal.

Referring again to FIG. 5, a space between the valve assembly 110 andthe valve actuator 123 receives the thermal conductor ring 156 and thethermal insulator gasket 157. The thermal insulator gasket 157 in someembodiments may partially overlap the thermal conductor ring 156. As aresult, the thermal conductor ring 156 may transfer heat from the end ofthe valve shaft 121 to the valve actuator 123, including to a region ofthe fluid cooling system 225. Advantageously, much less heat will betransferred from the valve shaft 121 to the actuator shaft 126 andinternal actuator components, such as motor windings.

The thermal conductor ring 156 is positioned between and is contacted bythe valve assembly 110 and by the valve actuator 123, wherein thethermal conductor ring 156 conducts heat from the valve assembly 110 tothe valve actuator 123. The thermal conductor ring 156 in someembodiments is positioned between and is contacted by the valve shaft121 of the valve assembly 110 and by an actuator inner mating portion182 of the valve actuator 123, wherein the thermal conductor ring 156conducts heat from the valve shaft 121 to the actuator inner matingportion 182 and wherein the actuator inner mating portion 182 of thevalve actuator 123 is in communication with the fluid cooling system225. The actuator inner mating portion 182 in some embodiments is inthermal communication with a cooling duct 227 or duct surface (seedashed lines) of the fluid cooling system 225.

At least a portion of the thermal insulator gasket 157 is clampedbetween the valve assembly 110 and the valve actuator 123 in someembodiments. The thermal insulator gasket 157 is consequently positionedbetween and contacted by the valve assembly 110 and the valve actuator123, wherein the thermal insulator gasket 157 blocks heat transfer fromthe valve assembly 110 to the valve actuator 123.

In some embodiments, the thermal insulator gasket 157 is positionedbetween and contacted by a valve outer mating portion 174 of the valveassembly 110 and an actuator outer mating portion 184 of the valveactuator 123, wherein the thermal insulator gasket 157 substantiallyblocks heat transfer from the valve outer mating portion 174 of thevalve assembly 110 to the valve actuator 123 and minimizes heat transferbetween the valve body 103 and the actuator housing 127. In addition,the thermal insulator gasket 157 may substantially seal the valve body103 to the actuator housing 127.

However, the thermal insulator gasket 157 allows heat transfer from thevalve assembly 110 to the valve actuator 123 through the thermalconductor ring 156. In some embodiments, the thermal insulator gasket157 allows heat transfer from the valve outer mating portion 174 to theactuator inner mating portion 182 via the thermal conductor ring 156.

FIG. 16 shows detail of the mating regions of the valve assembly 110 andthe valve actuator 123. This figure shows one or more interlockprotrusions 188 formed on and extending from the outward face of theactuator flange 124. Corresponding depressions are formed in the valveflange 105, wherein the valve actuator 123 and the valve assembly 110rotationally and positionally interlock when assembled together. The oneor more interlock protrusions 188 (and the corresponding interlockdepressions) can comprise one or more interlock features of any desiredshape and/or size. In addition, the one or more interlock protrusions188 pass through corresponding cut-outs 158 in the thermal insulatorgasket 157. Advantageously, the one or more interlock protrusions 188may be kept small, thereby minimizing metal-to-metal contact. Theminimization of metal-to-metal contact between the actuator 123 and thevalve assembly 110 will minimize the heat transfer therebetween.

We claim:
 1. A butterfly valve (100), comprising: a valve body (103)including a valve bore (109) passing through the valve body (103) and ashaft bore (112); a valve shaft (121) located in the shaft bore (112)and extending through the valve bore (109); at least one compressionring (152) located within the shaft bore (112), with the at least onecompression ring (152) substantially sealing the valve shaft (121) to anactuator-side shaft bore (112A).
 2. The butterfly valve (100) of claim1, with the at least one compression ring (152) comprising an at leastpartially resilient ring.
 3. The butterfly valve (100) of claim 1, withthe at least one compression ring (152) comprising a metallic ring. 4.The butterfly valve (100) of claim 1, further comprising a thermalconductor ring (156) fitted over an end of the valve shaft (121),wherein the at least one compression ring (152) fits partially into andextending partially out of a corresponding at least one ring groove(153) in the thermal conductor ring (156), with the at least onecompression ring (152) substantially sealing the thermal conductor ring(156) to the actuator-side shaft bore (112A).
 5. The butterfly valve(100) of claim 1, further comprising a thermal conductor ring (156)fitted over an end of the valve shaft (121), wherein the at least onecompression ring (152) fits partially into and extending partially outof a corresponding at least one ring groove (153) in the thermalconductor ring (156), with the at least one compression ring (152)substantially sealing the thermal conductor ring (156) to theactuator-side shaft bore (112A) and with the at least one compressionring (152) being removably mounted to the thermal conductor ring (156).6. The butterfly valve (100) of claim 1, further comprising a thermalconductor ring (156) fitted over an end of the valve shaft (121),wherein the at least one compression ring (152) fits partially into andextending partially out of a corresponding at least one ring groove(153) in the thermal conductor ring (156), with the at least onecompression ring (152) substantially sealing the thermal conductor ring(156) to the actuator-side shaft bore (112A) and with the at least onecompression ring (152) including a minimal tolerance with the at leastone ring groove (153).
 7. The butterfly valve (100) of claim 1, furthercomprising: a valve actuator (123) configured to couple to the valvebody (103), with the valve actuator (123) including an actuator shaft(126) configured to couple to the valve shaft (121); and a lip seal(159) positioned over the actuator shaft (126) of the valve actuator(123) and abutting the valve actuator (123), with the lip seal (159)being configured to prevent fluid from the valve bore (109) from passinginto the valve actuator (123) around the actuator shaft (126).
 8. Thebutterfly valve (100) of claim 1, further comprising a leakage returnconduit (163) extending through the valve body (103) from an valve innermating portion (172) to an interior valve bore surface (171), whereinthe leakage return conduit (163) is configured to return any leakagefluid present at the valve inner mating portion (172) to a downstreamvalve bore portion (109D).
 9. A butterfly valve (100), comprising: avalve body (103) including a valve bore (109) passing through the valvebody (103) and a shaft bore (112); a valve shaft (121) located in theshaft bore (112) and extending through the valve bore (109), with theshaft bore (112) including an actuator-side shaft bore (112A) and anon-actuator-side shaft bore (112B), with the actuator-side shaft bore(112A) extending from an interior valve bore surface (171) to an valveinner mating portion (172) of the valve body (103); a leakage returnconduit (163) extending through the valve body (103) from the valveinner mating portion (172) to the interior valve bore surface (171),wherein the leakage return conduit (163) is configured to return anyleakage fluid present at the valve inner mating portion (172) to adownstream valve bore portion (109D).
 10. The butterfly valve (100) ofclaim 9, wherein the leakage return conduit (163) is substantiallyparallel to the actuator-side shaft bore (112A).
 11. The butterfly valve(100) of claim 9, wherein the leakage return conduit (163) isnon-parallel to the actuator-side shaft bore (112A).
 12. The butterflyvalve (100) of claim 9, with the leakage return conduit (163) beingspaced a predetermined first distance D₁ from the actuator-side shaftbore (112A) at the valve inner mating portion (172).
 13. The butterflyvalve (100) of claim 9, with the leakage return conduit (163) beingspaced a predetermined second distance D₂ from the actuator-side shaftbore (112A) at the interior valve bore surface (171).
 14. The butterflyvalve (100) of claim 9, further comprising at least one compression ring(152) located within the shaft bore (112), with the at least onecompression ring (152) substantially sealing the valve shaft (121) to anactuator-side shaft bore (112A).
 15. The butterfly valve (100) of claim9, further comprising a thermal conductor ring (156) fitted over an endof the valve shaft (121), wherein the at least one compression ring(152) fits partially into and extending partially out of a correspondingat least one ring groove (153) in the thermal conductor ring (156), withthe at least one compression ring (152) substantially sealing thethermal conductor ring (156) to the actuator-side shaft bore (112A). 16.The butterfly valve (100) of claim 9, further comprising: a valveactuator (123) configured to couple to the valve body (103), with thevalve actuator (123) including an actuator shaft (126) configured tocouple to the valve shaft (121); and a lip seal (159) positioned overthe actuator shaft (126) of the valve actuator (123) and abutting thevalve actuator (123), with the lip seal (159) being configured toprevent fluid from the valve bore (109) from passing into the valveactuator (123) around the actuator shaft (126).
 17. A butterfly valve(100), comprising: a valve body (103) including a valve bore (109)passing through the valve body (103) and a shaft bore (112); a valveshaft (121) located in the shaft bore (112) and extending through thevalve bore (109); a valve actuator (123) configured to couple to thevalve body (103), with the valve actuator (123) including an actuatorshaft (126) configured to couple to the valve shaft (121); and a lipseal (159) positioned over the actuator shaft (126) of the valveactuator (123) and abutting the valve actuator (123), with the lip seal(159) being configured to prevent fluid from the valve bore (109) frompassing into the valve actuator (123) around the actuator shaft (126).18. The butterfly valve (100) of claim 17, with the lip seal (159) beingformed of an at least partially flexible material.
 19. The butterflyvalve (100) of claim 17, with the lip seal (159) being formed of an atleast partially resilient material.
 20. The butterfly valve (100) ofclaim 17, with the lip seal (159) being formed of an at least partiallycompressible material.
 21. The butterfly valve (100) of claim 17, withthe lip seal (159) comprising: a first annular seal portion (164)extending radially inward; a second annular seal portion (166) extendingradially inward and substantially parallel to the first annular sealportion (164); and a web portion (165) extending between and joining thesecond annular seal portion (166) to the first annular seal portion(164).
 22. The butterfly valve (100) of claim 17, further comprising atleast one compression ring (152) located within the shaft bore (112),with the at least one compression ring (152) substantially sealing thevalve shaft (121) to an actuator-side shaft bore (112A).
 23. Thebutterfly valve (100) of claim 17, further comprising a thermalconductor ring (156) fitted over an end of the valve shaft (121),wherein the at least one compression ring (152) fits partially into andextending partially out of a corresponding at least one ring groove(153) in the thermal conductor ring (156), with the at least onecompression ring (152) substantially sealing the thermal conductor ring(156) to the actuator-side shaft bore (112A).
 24. The butterfly valve(100) of claim 17, further comprising a leakage return conduit (163)extending through the valve body (103) from an valve inner matingportion (172) to an interior valve bore surface (171), wherein theleakage return conduit (163) is configured to return any leakage fluidpresent at the valve inner mating portion (172) to a downstream valvebore portion (109D).